A novel ACS fed multi band antenna loaded with mirrored S and L shaped strips for advanced portable wireless communication applications

摘要

A compact (0.15 lambda x 0.33 lambda) tri-band printed antenna with Asymmetric Coplanar Strip (ACS) feeding is proposed. The proposed structure is consisting of a half wavelength (0.5 lambda) meandered mirrored S shaped strip to excite the first resonant frequency at 2.35 GHz, a 0.29 lambda electrical length mirrored L shaped radiating branch is chosen to generate second operating at 3.45 GHz and an quarter wavelength (0.25 lambda) ACS monopole has been used to achieve third operating band centered at 5.2 GHz. All the three radiating branches with various optimized lengths have been chosen strategically to fulfill compact size feature. A prototype of the proposed design has been printed on a 1.6 mm thickness low cost substrate (FR4) and verified its performance characteristics experimentally. The measured and simulated results shows that the triple operating bandwidth with -10 dB return loss is about 180 MHz from 2.28-2.46 GHz, 300 MHz from 3.33-3.63 GHz and 350 MHz from 5.05-5.4 GHz, respectively. The proposed ACS fed tri band antenna is able to cover LTE 2300/2.3 GHz WiBro/RFID/WiBree/Zigbee/2.4/5 GHz ISM/2.4/5.2 GHz WLAN and 3.5 WiMAX applications. Further, the design offers omnidirectional radiation patterns with a constant peak gain of 1.85 dBi in the three operating bands.